The moves are part of a power struggle among Iran's political elite 30 years after the Islamic revolution. Analysts speculate that Supreme Leader Ayatollah Sayed Ali Khamenei is aiming to remove rival first-generation leaders – some of the original leaders of the revolution. President Mahmoud Ahmadinejad (a second-generation leader) is a useful ally in that effort.

On the other side, the anti-Ahmadinejad camp – motivated by dislike for the president's abrasive style, that they believe has damaged Iran's standing abroad – is striving to topple Ahmadinejad and preserve their own influence, and sometimes wealth, in Iran's opaque system of rule.

"Now we are entering the purge phase [of the revolution]," says a Western-educated analyst in Tehran. "So the [Supreme] Leader wants to eliminate all the first-generation revolutionaries. Ahmadinejad is a very effective representative to attack the credibility of these leaders."

In the mud-slinging presidential debates, Ahmadinejad made unprecedented public accusations of corruption and incompetence against his rivals – including the rich former president Ali Akbar Hashemi Rafsanjani, whom he beat in the last presidential election four years ago.

"Everyone was a loser," says the analyst. "They were all discredited."

Mr. Rafsanjani, a pillar of the regime since the 1979 Islamic revolution who heavily financed the Mousavi candidacy, chairs the 86-member Assembly of Experts that in theory has the power to remove the Supreme Leader. Numerous news reports indicate that Rafsanjani is trying to call the assembly into emergency session.

Two sides in a power play

The power play is taking place among the ruling elite, with all players committed to the Islamic system. Yet hard-line President Ahmadinejad hails from a second-generation of ideologically driven leaders.

Shaped by the Iran-Iraq War of the 1980s, they have brought the Revolutionary Guards and ideological basiji militia into government like never before – resulting in a deliberate "securitization" of Iranian society. With them are a number of arch conservative clerics.

Even before the fiercely contested June 12 vote, in which Ahmadinejad was officially declared the winner by a large margin amid charges of massive fraud, Iran's Revolutionary Guard Corps warned that Mousavi supporters banding together with political excitement on the streets were part of a "velvet revolution" that would "not be successful in Iran."

Mr. Mousavi, a former prime minister in the 1980s who clashed frequently with Khamenei – who was then president – is joined in the anti-Ahmadinejad camp by former president Mohamad Khatami. With them are also the two presidential candidates who were given a paltry number of votes, former parliament speaker Mehdi Karroubi and war-time Revolutionary Guard commander Mohsen Rezaie.

A number of clerics in Qom, a city of Shiite scholarship, are also aligned against Ahmadinejad. They include Iran's leading dissident Grand Ayatollah Hossein Ali Montazeri – once the chosen heir of Ayatollah Ruhollah Khomeini – who said on his website that "no one in their right mind can believe" the results, and that "a government not respecting the people's vote has no religious or political legitimacy."

Supreme leader's dilemma

Indeed, analysts say Iran's top leader is in a dilemma, thanks to his strikingly quick confirmation of the Ahmadinejad victory – and, many protesters believe, his role engineering of the result. Just days before the vote, Rafsanjani warned Khamenei in an open letter to take "serious action" against Ahmadinejad and his accusations, or risk "fire ... flaring during and after the election."

"This is a very fluid, unpredictable, improvised moment, and I don't know where it's going to go, but I [do] know some people have to pay for this; we just don't know who," says Farideh Farhi, an expert on Iranian politics at the University of Hawaii. "Whether it's going to be the Rafsanjani crowd ... or Mr. Ahmadinejad, the bottom line is I think Mr. Khamenei will pay for this. He has mishandled this election in a very serious way."

Wednesday morning, Khamenei took the unprecedented step of meeting representatives of all four candidates and the Guardian Council, which is expected to reexamine part of the vote in the coming week.

"[Khamenei] shows by his actions that he was directly involved," says a journalist in Tehran, who could not be named for security reasons but has seen clashes in his neighborhood every night. "Their mentality is swollen with illusions about the enemy, they are trying to find the supposed leaders.... Anyway, this is what it takes for a new order to emerge, one shaped by the supreme leader, totally characterized by his own ambitions."

The problem is the scene on the streets, he says: "Even if they get away with it, and Ahmadinejad survives, their legitimacy has taken a serious blow."